When does the day of the Lord begin and how long does it last?
The day of the Lord begins with the start of the tribulation and continues all the way through until believers enter eternity. It is not limited to a single event or short period, but extends from the tribulation onward, encompassing the dissolution of the heavens and earth.
Les explains that the day of the Lord is the beginning of the tribulation all the way on through until we go into eternity. He connects it with II Peter 3, where the heavens shall pass away with a great noise, the elements shall melt with fervent heat, and the earth and its works shall be burned up. Since all these things will be dissolved, he asks what manner of persons ought ye to be in all holy conversation and godliness, looking for and hasting unto the coming of the day of God, wherein the heavens being on fire shall be dissolved. Les says he is beginning to believe more and more that this whole universe is going to be totally melted down and brought right back to the very God that created it. He recalls a scientific journal article by a famous physicist who concluded that everything came from an original source of light, and from that source all the universe came into being.